Children are less prone to catch the Covid-19 disease. Within households in China their chance of getting infected was only 30% of the average chance for all household members. For individuals over 65 years of age the chance was 150% of the household average. Children who catch the Coronavirus have in general only very mild systems. But they carry the same load of viruses as grownups do. That means that they are generally as infectious as adults.

During a normal school day a child will have often intense contact with some 47 other individuals. Typical adults only have some 15 inter-human contacts during a normal work day. That is why children, even when less susceptible to the disease, are still a very important epidemic vector. While closing schools can not completely interrupt an epidemic and is expensive it can lower the epidemic’s peak by some 60%.—

There were reports from South Korea that recovered Covid-19 patients had again caught the disease. This was always unlikely to be true.To test the patients the usual RT-PCR test was used. That test does not directly look for the virus but for distinct sections of its genetic RNA code.

But recovered patients may continue toshed non-infectious virus debrisfor several months. Professor Drosten, the now famous German coronavirus specialist, explained in one of his podcasts that it takes a while until clotted parts of the lungs reopen. When they do the virus debris contained in those parts will be shed just by normal breathing. An RT-PCR test may show these patients as positive but we can be sure that they are cured.

South Korea has now used other tests to confirm that those ‘re-infected persons’ were indeed cured and no longer infectious.

Another Chinese study found that all people they tested who successfully recuperated from Covid-19 haddeveloped antibodies:

“Within 19 days after symptom onset, 100% of patients tested positive for antiviral immunoglobulin-G (IgG). Seroconversion for IgG and IgM occurred simultaneously or sequentially. Both IgG and IgM titers plateaued within 6 days after seroconversion.”

That both types of antibodies reliably occur is very good news. We know from human reactions to other coronaviruses that these antibodies give immunity for at least a year.Even after that the body will react to a new infection much faster to find and kill the virus than in people who catch the virus for the first time. The symptoms of the second infection will therefore be much milderthan those of the first one.

It is likely that the immunity will stay even longer than a year because the novel Coronavirus is so far less prone to mutatethan the typical influenza viruses:

“In fact, researchers have found that the coronavirus is mutating relatively slowly compared to some other RNA viruses, in part because virus proteins acting as proofreaders are able to fix some mistakes. Each month, a lineage of coronaviruses might acquire only two single-letter mutations….

That bodes well for vaccines currently in development for Covid-19. If people get vaccinated in 2021 against the new coronavirus, they may well enjoy a protection that lasts for years.”

The genetic code of the novel Coronavirus is about 30,000 letters long. Two modifications per month per strain are unlikely to change its immune-system appearance or function. A vaccine that creates sufficient antibodies will likely be long lasting.—

The evidence is piling up that severe cases of the Covid-19disease are related to an unusual immune system response caused by the SARS-CoV-19 virus:

“Benjamin tenOever at the Icahn School of Medicine at Mount Sinai in New York City and his colleagues found that cells infected with SARS-CoV-2 produce unusually low levels of antiviral proteins called interferons compared with cells infected with other respiratory viruses (D. Blanco-Melo et al. Cell https://go.nature.com/3bWE82b, 2020). But levels of some proteins, such as IL-6, that activate more general immune responses are higher in infected ferrets and people than in uninfected controls.”

During the outbreak in Hubei province one local Chinese hospital tested a new way to keep its staff healthy. It used the human interferon alpha, an immune system related messenger substance, in nasal drops applied four times a day. Out of nearly 3,000 staff, a third of whom cared for Covid-19 cases, none got infected. While this was not a randomized double blind study it points into an interesting direction.

Nicotine can also play a role in balancing the immune system response in Covid-19 cases. Smokers have been the accidental guinea pigs that allowed for these findings:

“A quarter of French adults smoke. Many people were surprised, therefore, when researchers reported late in April that only 5% of 482 covid-19 patients who came to the Pitié-Salpêtrière hospital in Paris between February 28th and April 9th were daily smokers. The ratios of smokers to non-smokers in earlier tallies at hospitals in America, China and elsewhere in France varied. But all revealed habitual smokers to be significantly underrepresented among those requiring hospital treatment for the illness.”

A new paper in Science Direct explains in detail why this may indeed happen. If the SARS-CoV-19 virus is not defeated early and replicates in huge numbers it imbalances the mixture of chemical messengers substances that keep the immune system under control. Then a so called cytokine storm happens and the immune system starts to attack the inner organs. This explains why doctors see such a wide range of different organ failures in critical Covid-19 cases….

Some groups in France have started randomized studies with nicotine patches as therapy for Covid-19 cases.”…